Question: What is an SI derived unit that starts with the letter w.
Paraphrase: What is an SI inferred unit that begins with the letter w.
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q208469 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 'w')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
Answer: watt per square metre nanometre, watt per square metre nanometre, watt per steradian square metre nanometre, watt per steradian square metre nanometre, weber, weber, watt, watt, watt per square metre kelvin, watt per square metre kelvin, watt per square metre kelvin to the fourth power, watt per square metre kelvin to the fourth power, watt per kilogram, watt per kilogram, watt per metre kelvin, watt per metre kelvin